Probiotics have long been hailed as the ultimate support for the immune and digestive systems, and there is no doubt of their ability to promote and maintain a healthy gut. However, despite their fame, a little-known truth is that probiotics would be of little effect without their less-celebrated partner: prebiotics, or prebiotic fiber to be exact. Here we’ll discuss what is prebiotic fiber, how it helps probiotics, and why you need to include it as part of your diet.

What Is Prebiotic Fiber?

Although the term “prebiotic” is fairly new (coined in 1995), prebiotics themselves are nothing new.[1]Prebiotics are an indigestible form of fiber found in some (but not all) fruits, vegetables, and starches. They act as a food source for the friendly bacteria in the gut. It is important to note that though every prebiotic is a fiber, not every fiber is a prebiotic. To be considered “prebiotic” in nature, a fiber must meet the following criteria:[2]

Resists digestion and absorption in the upper gastrointestinal tractIs fermented by the intestinal microfloraSelectively stimulates the growth or activity of friendly intestinal bacteria

You Can’t Have Probiotics Without Prebiotics

Prebiotics and probiotics have a symbiotic relationship. Prebiotic fiber is the main food source of probiotics, and probiotics cannot thrive without it. Ingesting a probiotic supplement or food with prebiotic fiber places the indigestible prebiotics in the gut where probiotics consume them. This helps those beneficial bacteria populate your gut microbiome.[3] Conversely, if a probiotic is consumed without prebiotic fiber, it’s less likely to flourish.

The Health Benefits of Prebiotics

Though the scientific understanding of prebiotics is relatively young, promising discoveries have surfaced about their health benefits. The following is just a small sampling of the findings from research into the health benefits of prebiotics.

Encourages Gut Health and Diversity

Per a study published in The Journal of Nutrition, prebiotics and probiotics support gut health diversity and digestive health.[4] This is just one of many studies to show that prebiotic fiber is integral for a healthy, balanced gut.[5]

Promotes Bone Health

Studies, including those published in The British Journal of Nutrition, show that prebiotic fiber improves absorption of all minerals in the body, including bone-healthy magnesium and calcium.[5, 6]

Supports Cardiovascular Health

Prebiotics have a beneficial effect on lipid metabolism, and they can help ease systemic redness to support normal cardiovascular health.[5, 7]

Helps Control Appetite and Weight Management

Studies published in the British Journal of Medicine and the American Journal of Clinical Nutrition have shown that prebiotics can help with appetite control by increasing satiety hormones, making you feel less hungry.[8, 9]

Regulates Insulin Sensitivity

A study published in The Journal of Nutrition showed consumption of 15 to 30 grams of resistant starch (a type of prebiotic fiber) a day reduced insulin resistance in obese and overweight men.[10]

Sharpens Brain Function

According to Trends in Neuroscience, prebiotics are considered a form of “psychobiotic,” which exert beneficial effects on gut bacteria and positively impact the gut-brain-axis.[11]

Brightens Mental and Emotional Health

In addition to their psychobiotic mental health benefits, the results of human and animal studies found that prebiotic fibers support normal mental and emotional health and stress response.[12]

Promotes Restful Sleep

As reported by researchers from the University of Colorado, regular consumption of prebiotics can help boost the amount of REM and non-REM sleep in animals after a stressful event.[12, 13]

What Are the Different Types of Prebiotics?

Prebiotics exist in both food and supplement form. Common examples of prebiotic fiber you will find in supplements and food include:

Acai gumInulinLactuloseLafinoseOligosaccharides (the best-known prebiotics) including:Fructooligosaccharides (FOS)Oligofructose (OF)Galactooligosaccharides (GOS)Transgalactooligosaccharides (TOS)PolydextrosePsylliumResistant starch (RS)Wheat dextrinWhile there’s debate over which prebiotics are the most effective, it is clear that ingesting any prebiotics with probiotics or cultured foods is beneficial.

What Is a Prebiotic Supplement?

Prehistoric hunter-gatherers ingested many prebiotic-containing foods, such as desert plants.[2] If you have not carried on that tradition and you don’t ingest enough prebiotic-rich foods in your diet, supplementation can fill the gaps.

Prebiotics are available as stand-alone supplements or combined with a probiotic formula to enhance its effectiveness. Depending upon your goals, you may wish to take a combination product or a pure prebiotic. Keep in mind that a probiotic must be taken with a prebiotic (either as a supplement or food) to be effective, but a prebiotic can provide stand-alone health benefits.

The Best Prebiotic Foods That Everyone Should Eat

Since prebiotics are relatively “new” on the health and science scene, there is some debate over which foods qualify as “prebiotic foods” and which don’t. Some health care professionals and scientists believe that any fiber-containing food could have prebiotic benefits. That may be true, but, for now, we’ll focus on the “official” best prebiotic foods.[14, 15]

Asparagus—consumed in its whole, fibrous state.Bananas—offer a good serving of resistant starch when consumed slightly unripe.Chicory root—rich in inulin and a popular choice among probiotic manufacturers, chicory root also doubles as a delicious coffee substitute.Garlic—excellent for supporting the immune system and gut health.Jerusalem artichoke—also known as “sunchokes,” these potato-like tubers have a delicate flavor and are brimming with prebiotic fiber.Leeks—are prized for their health properties and prebiotic value.Onions—another immune system and gut-health champion.Potato starch—if you’ve ever wondered why potato starch is prevalent in natural food stores, it is partly because of its value as a resistant starch.Soybeans—though I generally recommend avoiding soy products, whole soybeans are a good source of prebiotic fiber. If you do eat soy, consume it sparingly and look for organic, non-GMO, fermented soy products like tempeh and miso.Whole grain corn—look for organic, non-GMO, sprouted corn products.Whole grains—such as oats.It is worth noting that prebiotics are also abundant in breast milk and help babies build good gut bacteria, a benefit that’s thought to help protect infants from infections.[16]

How Many Prebiotic Foods Should You Consume Daily?

Your natural health care professional can help you determine the best diet plan based on your current state of health and your goals. Based on my experience and the current research, I recommend consuming at least one or two prebiotic-rich foods a day to help maintain good gut health. This is in addition to a diet that’s already rich in fruits and vegetables—which may offer additional prebiotic benefits. An easy solution is to eat soups with onions and garlic, substitute Jerusalem artichokes for potatoes, and blend bananas or resistant starch (like potato starch) into your smoothies. Don’t forget to make sure that your probiotic supplement contains prebiotic fiber.

Prebiotics: The Bottom Line

To recap, prebiotics are the primary food source for probiotics and are just as important as probiotics (if not more so). Probiotics cannot flourish in your gut without prebiotics. Prebiotic supplements may be taken as stand-alone products, or combined with a probiotic like FloraTrex™. FloraTrex combines 23 different probiotics with the right amount of prebiotics to help support your gut health. No more worrying about separate supplements or adding specific foods to your diet.

Are prebiotics on your radar? What insight can you provide? Leave a comment below and share your thoughts with us.